1. Field of the Invention
The present invention relates to an etching method. More particularly, the present invention relates to a method for high-density plasma etching.
2. Description of the Related Art
In the device patterning process, to enhance the photosensitivity contrast, amine compounds are often added into a photo-resist layer. While performing the conventional etching process using a high density plasma (HDP) oxide etcher, a high intensity ultraviolet (UV) radiation is generated. It is found that the amine compounds from the photo-resist materials would be decomposed under the high-intensity UV radiation and produce nitrogen gas. Resist bubblings are thus occurred in the photo-resist layer by the diffusion of the nitrogen gas. Being obstructed by a barrier layer formed on the photo-resist layer, the bubbles of the nitrogen gas are further retained in the photo-resist layer instead of sweating out. After accumulated a certain concentration or pressure to certain, a pressure burst is easily caused.